Virtual reality is collectively referred to as an interface between a human and a computer, which produces a specific environment or situation with stereoscopic 3D contents through the computer and creates as if a person who uses the 3D contents interacts with an actual surrounding situation or environment, etc.
In general, a three-dimensional effect perceived by the person is achieved by complex operation of a degree of thickness change of a lens depending on the position of an observed object, an angle difference between both eyes and the object, a difference in position and shape of the object seen in right and left eyes, a disparity caused depending on movement of the object, an effect by various psychologies and memories, and the like.
The most important factor through which the person feels the 3D effect among them is a binocular disparity caused as both eyes of the person are horizontally separated from each other by approximately 6.5 cm. That is, the person views the object with the angle difference for the object by the binocular disparity and images input into respective eyes have different phases due to such a difference and when both images are transferred to a brain through a retina, the brain accurately fuses the two pieces of information, and as a result, a user may feel an original 3D stereoscopic image. These stereoscopic 3D contents have been widely used in various media fields and have been popular with consumers. For example, 3D movies, 3D games, and experience displays are representative.
As described above, in addition to the universalization of virtual reality technology 3D contents, there is a multilateral need to develop a technology capable of providing a more immersive virtual reality service.